SCIURIDA—TAMIAS HARRISI. 811 
lighter anteriorly and more vinaceous posteriorly, with a narrow white line on 
each side extending from the shoulder to the hip. Ring surrounding the eye 
and lower parts pale yellowish-white, varying to clear white. Sides of the 
body below the white line, especially on the limbs externally, washed with 
a pale shade of chestnut. Tail flat; above, black, varied and edged with 
white; lower surface white centrally and at the edges, with a subterminal bar 
of black. The hairs of the sides of the tail and some of those of the upper 
surface are black at the extreme base as well as subterminally. Ears small, 
pointed, clothed with short hairs. Soles partly naked in summer, well clothed 
in winter. The winter pelage (especially at the northward) is full, soft, and 
silky ; that of the back mostly white beneath the surface. In summer, par- 
ticularly in Cape Saint Lucas specimens, the pelage is very short, stiff, and 
harsh. 
In this species, the variations in color are very slight. The light mark- 
ings range from nearly pure white to soiled yellowish-white; the sides vary 
slightly in the amount of chestnut they present, and the prevailing tint of the 
dorsal surface varies from gray to pale vinaceous. ‘The hairs are black at the 
base; those of the dorsal surface, in winter, are mainly white below the sur- 
face, with narrow basal and subterminal bars of black and yellowish-gray 
tips. In summer specimens, the pelage is very short and stiff, with no under 
fur; in winter, long, very soft, with an abundance of silky under fur. 
The present species differs from the other members of the group mainly 
in having much smaller ears, a shorter tail than either 7. asiaticus or T. stri- 
atus, and in wholly lacking the black dorsal stripes present in all the others. 
The absence of these, as well as its short ears, serves at once to distinguish 
it among its congeners. It is, in the average, rather smaller than T- striatus, 
but rather exceeds in size the smaller varieties of J. astaticus. It also dif- 
fers somewhat in habits and in the form of the angle of the lower jaw. It 
might, in fact, perhaps stand as the type of a new subgenus, coming nearer 
to Tamias than to Spermophilus. Its chief points of difference from the typ- 
ical Ground Squirrels consist in its smaller ears and in the very much greater 
development of the angle of the mandibular ramus, which gives rise to a 
more strongly marked ascending square process at the posterior upper border, 
Tamias harrisi was first described by Audubon and Bachman in 1854, 
from a single specimen obtained by Mr. J. K. Townsend on his journey to 
Oregon, but the precise locality was unknown. Its habitat was first accu- 
